A method of mass and/or ion mobility spectrometry is disclosed that includes ionising analyte from a sample so as to generate a plurality of ions, separating precursor ions from first fragment and/or other ions of the plurality of ions, fragmenting or reacting at least some of the precursor ions using a fragmentation, reaction or collision device so as to generate second fragment ions, and then analysing at least some ions that emerge from the fragmentation, reaction or collision device. The sample is classified and/or identified based on the analysis of the second fragment ions.

The invention generally relates to ion generation using modified wetted porous materials. In certain aspects, the invention generally relates to systems and methods for ion generation using a wetted porous substrate that substantially prevents diffusion of sample into the substrate. In other aspects, the invention generally relate to ion generation using a wetted porous material and a drying agent. In other aspects, the invention generally relates to ion generation using a modified wetted porous substrate in which at least a portion of the porous substrate includes a material that modifies an interaction between a sample and the substrate.

A system and method are provided for loading a sample into an analytical instrument using acoustic droplet ejection (“ADE”) in combination with a continuous flow sampling probe. An acoustic droplet ejector is used to eject small droplets of a fluid sample containing an analyte into the sampling tip of a continuous flow sampling probe, where the acoustically ejected droplet combines with a continuous, circulating flow stream of solvent within the flow probe. Fluid circulation within the probe transports the sample through a sample transport capillary to an outlet that directs the analyte away from the probe to an analytical instrument, e.g., a device that detects the presence, concentration quantity, and/or identity of the analyte. When the analytical instrument is a mass spectrometer or other type of device requiring the analyte to be in ionized form, the exiting droplets pass through an ionization region, e.g., an electrospray ion source, prior to entering the mass spectrometer or other analytical instrument. The method employs active flow control and enables real-time kinetic measurements.

The invention provides hybrid mass spectrometric systems which comprise an ion source, a first trapped ion mobility spectrometry (TIMS) analyzer and a mass analyzer, wherein the TIMS analyzer is located and operated in a first vacuum chamber at an elevated pressure above 500 Pa, and methods for operating the hybrid mass spectrometric systems.

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to a vibrating sharp edge spray ionization (VSSI) method suitable for coupling with a mass spectrometer, a VSSI method modified with a capillary suitable for use with continuous-flow separation methods such as liquid chromatography, and a VSSI method suitable for coupling with a capillary electrophoresis (CE) device in order to introduce the CE sample flow into a mass spectrometer. Also disclosed herein are devices for carrying out these methods and methods of making the same. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

A mass spectrometry method comprises: receiving a stream of ions at an inlet end of an ion transport device; accumulating a first portion of the ion stream at a first electrical potential well at a first position within the ion transport device between the inlet and outlet ends; creating a generally descending potential profile within the ion transport apparatus between a second position and the outlet end and, simultaneously, creating a second potential well at a third position within the ion transport apparatus, the second position disposed between the first position and the inlet end, the third position disposed between the second position and the inlet end; and transporting the accumulated first portion of the ion stream from the first position to the outlet end under the impetus of the generally descending potential profile and, simultaneously, accumulating a second portion of the ion stream at the second potential well.

This disclosure provides methods, systems, and compositions of matter for studying solvent accessibility and three-dimensional structure of biological molecules. A plasma can be used to generate marker radicals, which can interact with a biological molecule and mark the solvent-accessible portions of the biological molecule.

Provided are methods for determining the amount of estradiol in a sample using mass spectrometry. The methods generally involve ionizing estradiol in a sample and detecting and quantifying the amount of the ion to determine the amount of estradiol in the sample.

A method of performing mass spectrometry includes accumulating, over an accumulation time, ions produced from components eluting from a chromatography column and transferring the accumulated ions to a mass analyzer. During an acquisition, a mass spectrum of detected ions derived from the transferred ions is acquired. An elution profile is obtained from a series of acquired mass spectra including the acquired mass spectrum and a plurality of previously-acquired mass spectra. The elution profile includes a plurality of detection points representing intensity of the detected ions as a function of time. A current signal state of the elution profile is classified based on a subset of detection points included in the plurality of detection points. The accumulation time for a next acquisition of a mass spectrum is set based on the classified current signal state of the elution profile.

In an inductively coupled plasma-mass spectrometry (ICP-MS) system, ions are transmitted into a collision/reaction cell. A DC potential is applied at an exit of the cell at a first magnitude to generate a DC potential barrier effective to prevent the ions from exiting the cell. The DC potential barrier is maintained during a confinement period to perform an interaction. After the confinement period, analyte ions or product ions are transmitted to a mass spectrometer by switching the exit DC potential to a second magnitude effective to allow the analyte ions or product ions to pass through the cell exit as a pulse. The analyte ions or product ions are then counted during a measurement period. The interaction may be ion-molecule reactions or ion-molecule collisions.